Women who believe they have overcome breast cancer are being failed "every step of the way" when they experience symptoms of the disease coming back, a damning report has found.
The study, for the charity Breast Cancer Care, said some women had their concerns - such as back and bone pain - ignored by their GP for months, with a fifth given treatment for something else.
The charity also heard from women who were given months of physiotherapy or painkillers instead of investigations for cancer, and women being first told they have advanced breast cancer in A&E.
The new report says thousands of patients with incurable breast cancer across England, Scotland and Wales could be receiving "second-rate care".
The study is based 840 women who were eventually told they have advanced, incurable breast cancer - one of the biggest studies of its kind.
Of these, 72% had had a previous diagnosis of primary breast cancer, while 28% learned they had breast cancer when it had already begun to spread to other parts of their body.
Overall, 8% were told the news in A&E, suggesting "some people are left struggling with uncontrolled symptoms that become so debilitating they are rushed to hospital", the report said.
A fifth (20%) of those surveyed said that, despite thinking something might be wrong, it was eight weeks or more before they saw a hospital doctor.
Almost a third (31%) did not feel healthcare professionals listened to their concerns about having the disease.
The report also found that awareness of advanced cancer is low, even among those who have had an initial diagnosis and treatment for breast cancer.
Some 64% did not suspect they had advanced cancer, while only 8% said they fully expected their diagnosis.
Even among those that had a previous diagnosis of primary breast cancer, over half (56%) did not think it had come back.
But almost six in 10 (58%) did not know how to spot signs and symptoms of the disease and most were not told how to get back in touch with hospitals if they suspected something was wrong.
Samia al Qadhi, chief executive of Breast Cancer Care, said: "Today's report paints an extremely worrying picture. Our findings uncover the true extent of inadequate care for people with incurable breast cancer - from feeling they're not taken seriously when they raise concerns, to facing avoidable delays to a diagnosis, or being told the news in A&E. This is absolutely unacceptable.
"Prompt diagnosis is crucial to help control severe symptoms and allow people with incurable breast cancer to make every day count - as a mum or grandmother, at work, and when making memories with friends. Yet, for so many this is not happening."
Mother-of-one Emma Cairns, 43, from Wokingham, Berkshire, was diagnosed with advanced breast cancer in 2011. She said: "I started getting really bad back ache about four years after my primary breast cancer. Tests at my GP came back okay and I was told to get on with things. But the pain continued to get worse. After going back and forth and even with three months of physiotherapy, it wasn't any better. I still didn't get an MRI scan.
"A year-and-a-half later I could barely walk. Finally an MRI was arranged and I was still reassured it was probably nothing. Then, after the scan I was told I had incurable breast cancer. Not only that, I had three collapsed vertebrae and the cancer was in my pelvis and liver. I was distraught.
"I'd been made to feel I was making a fuss about nothing and now I was facing my worst nightmare."
Mother-of-three Claire McDonnell, 43, from Reading, Berkshire, was diagnosed with advanced breast cancer in November 2013. She said: "I wasn't told anything about looking out for signs and symptoms of the cancer returning after my primary breast cancer diagnosis. I didn't know bone pain could be a warning sign. And when I started getting a stabbing pain in my sternum I went to my GP and was prescribed painkillers.
"After a year I went to see my oncologist. I thought tests would rule out anything serious. Instead I was told my cancer was back, had spread around my body and was incurable. There was little support and I was in total shock. It was devastating to think it could have been spotted earlier."